Water quality in the Floridan Aquifer Region

We rely on clean water to sustain human life, ecosystems, and food supply. In Florida and southwest Georgia, the Floridan Aquifer supplies much of the water we use. As populations grow and regional economies expand, the impacts of human activity on water pollution become more widespread. We must take preventative actions to minimize water pollution to maintain the quality of our water sources, and thus, our quality of life.

Water availability in southwest Georgia and northeast Florida

Stretching from Mississippi to South Carolina, the Floridan Aquifer is the main source of freshwater for southwest Georgia and north Florida. It provides drinking water for approximately 10 million people, supports agriculture and tourism, and sustains the ecosystem. The aquifer’s capacity is large but limited, and meeting the area's water demands will require balancing withdrawals from the aquifer with replenishment from rainfall, a particularly difficult problem in drier times.

Spatial and Temporal Dynamics of Prokaryotic and Viral Community Assemblages in a Lotic System, Manatee Springs, Florida

Flow from high magnitude springs fed by the Floridan aquifer system contribute hundreds of liters of water per second to rivers, creating unique lotic systems. Despite their importance as freshwater sources and their contributions to the state’s major rivers, little is known about the composition and spatiotemporal variability of prokaryotic and viral communities of these spring systems or their influence on downstream river sites. At four time points throughout a year, we determined the abundance and diversity of prokaryotic and viral communities at three sites within the first-magnitude Manatee Springs system (the spring head where water emerges from the aquifer, a mixed region where the spring run ends, and a downstream site in the Suwannee River). The abundance of prokaryotes and virus-like particles increased 100-fold from the spring head to the river and few members from the head communities persisted in the river at low abundance, suggesting the springs play a minor role in seeding downstream communities. Prokaryotic and viral communities within Manatee Springs clustered by site, with seasonal variability likely driven by flow. As water flowed through the system, microbial community composition was affected by changes in physiochemical parameters and community coalescence. Evidence of species sorting and mass effects could be seen in the assemblages. Greater temporal fluctuations were observed in prokaryotic and viral community composition with increasing distance from the spring outflow, reflecting the relative stability of the groundwater environment, and comparisons to springs from prior work reaffirmed that distinct first magnitude springs support unique communities. Importance Prokaryotic and viral communities are central to food webs and biogeochemical processes in aquatic environments, where they help maintain ecosystem health. The Floridan aquifer system (FAS), which is the primary drinking water source for millions of people in the southeastern United States, contributes large amounts of freshwater to major river systems in Florida through its springs. However, there is a paucity of information regarding the spatiotemporal dynamics of microbial communities in these essential flowing freshwater systems. This work explored the prokaryotic and viral communities in a first-magnitude spring system fed by the FAS that discharges millions of liters of water per day into the Suwannee River. This study examined microbial community composition through space and time, as well as the environmental parameters and metacommunity assembly mechanisms that shape these communities, providing a foundational understanding for monitoring future changes.